Restore purchase flow

android/app/src/main/kotlin/org/getlantern/lantern/handler/MethodHandler.kt

@@ -45,6 +45,7 @@ enum class Methods(val method: String) {
     StripeBillingPortal("stripeBillingPortal"),
     Plans("plans"),
     AcknowledgeInAppPurchase("acknowledgeInAppPurchase"),
+    RestoreInAppPurchase("restoreInAppPurchase"),
     PaymentRedirect("paymentRedirect"),
     ReportIssue("reportIssue"),
 
@@ -465,6 +466,26 @@ class MethodHandler : FlutterPlugin,
                 }
             }
 
+            Methods.RestoreInAppPurchase.method -> {
+                scope.launch {
+                    result.runCatching {
+                        val map = call.arguments as Map<*, *>
+                        val restoreData = Mobile.restoreGooglePlayPurchase(
+                            map["purchaseToken"] as String,
+                        )
+                        withContext(Dispatchers.Main) {
+                            success(restoreData.toByteArray(Charsets.UTF_8))
+                        }
+                    }.onFailure { e ->
+                        result.error(
+                            "restore_in_app_purchase",
+                            e.localizedMessage ?: "Please try again",
+                            e
+                        )
+                    }
+                }
+            }
+
             Methods.PaymentRedirect.method -> {
                 scope.launch {
                     result.runCatching {

assets/locales/en.po

@@ -1038,6 +1038,15 @@ msgstr "Enter an Activation Code"
 msgid "restore_purchase"
 msgstr "Restore Purchase"
 
+msgid "already_purchased"
+msgstr "Already purchased?"
+
+msgid "restore_purchase_success"
+msgstr "Purchase restored successfully."
+
+msgid "restore_purchase_no_purchases"
+msgstr "No purchases were found to restore."
+
 
 msgid "do_private_server_setup"
 msgstr "DO Private Server Setup"

go.mod

@@ -2,7 +2,7 @@ module github.com/getlantern/lantern
 
 go 1.26.2
 
-// replace github.com/getlantern/radiance => ../radiance
+replace github.com/getlantern/radiance => ../radiance
 
 // replace github.com/getlantern/lantern-server-provisioner => ../lantern-server-provisioner
 

go.sum

@@ -261,8 +261,6 @@ github.com/getlantern/pluriconfig v0.0.0-20251126214241-8cc8bc561535 h1:rtDmW8YL
 github.com/getlantern/pluriconfig v0.0.0-20251126214241-8cc8bc561535/go.mod h1:WKJEdjMOD4IuTRYwjQHjT4bmqDl5J82RShMLxPAvi0Q=
 github.com/getlantern/publicip v0.0.0-20260328175246-2c460fe80c6b h1:gMYJzEhLrmIqQ+JnjiYNm+UyUDalK3WUmVyecFwmV5g=
 github.com/getlantern/publicip v0.0.0-20260328175246-2c460fe80c6b/go.mod h1:NpfXdK4ldEKkjQ4P1R+DBF4ua5VFOlxmgHROTnYrApg=
-github.com/getlantern/radiance v0.0.0-20260507232251-71c8a8b5b1c2 h1:O6B+kPVuHOPFayuiRZhBz0EqPPnXSf/NlbftgMaVIPY=
-github.com/getlantern/radiance v0.0.0-20260507232251-71c8a8b5b1c2/go.mod h1:oBXKRBE6qxdBmxnjV9NI3CSOSy4zDlm1f7haUVWpwBQ=
 github.com/getlantern/samizdat v0.0.3-0.20260327203406-ef7323341974 h1:k+/qNo5YNO+8M8LVUp6G5Evm1OQdEs3Z4ye8top4AhI=
 github.com/getlantern/samizdat v0.0.3-0.20260327203406-ef7323341974/go.mod h1:uEeykQSW2/6rTjfPlj3MTTo59poSHXfAHTGgzYDkbr0=
 github.com/getlantern/semconv v0.0.0-20260327040646-21845dda05cb h1:c5YM7b3a4r2J8Eh89KkI6M/iTFe6Bi+b8AJlfkKdFq4=

ios/Runner/Handlers/MethodHandler.swift

@@ -92,6 +92,22 @@ class MethodHandler {
         }
         self.acknowledgeInAppPurchase(token: token, planId: planId, result: result)
 
+      case "restoreInAppPurchase":
+        guard
+          let map = call.arguments as? [String: Any],
+          let token = map["purchaseToken"] as? String
+        else {
+          result(
+            FlutterError(
+              code: "INVALID_ARGUMENTS",
+              message: "Missing or invalid purchaseToken",
+              details: nil
+            )
+          )
+          return
+        }
+        self.restoreInAppPurchase(token: token, result: result)
+
       // user management
       case "startRecoveryByEmail":
         let map = (call.arguments as? [String: Any]) ?? [:]
@@ -553,6 +569,20 @@ class MethodHandler {
     }
   }
 
+  func restoreInAppPurchase(token: String, result: @escaping FlutterResult) {
+    Task {
+      var error: NSError?
+      let json = MobileRestoreApplePurchase(token, &error)
+      if let error {
+        await self.handleFlutterError(error, result: result, code: "RESTORE_FAILED")
+        return
+      }
+      await MainActor.run {
+        result(json.data(using: .utf8))
+      }
+    }
+  }
+
   // MARK: - User management
 
   func startRecoveryByEmail(result: @escaping FlutterResult, email: String) {

lantern-core/core.go

@@ -122,6 +122,8 @@ type Payment interface {
 	StripeBillingPortalUrl() (string, error)
 	AcknowledgeGooglePurchase(purchaseToken, planId string) (string, error)
 	AcknowledgeApplePurchase(receipt, planII string) (string, error)
+	RestoreGooglePlayPurchase(purchaseToken string) (string, error)
+	RestoreApplePurchase(receipt string) (string, error)
 	PaymentRedirect(provider, planID, email string) (string, error)
 	ActivationCode(email, resellerCode string) error
 	SubscriptionPaymentRedirectURL(redirectBody account.PaymentRedirectData) (string, error)
@@ -871,6 +873,36 @@ func (lc *LanternCore) AcknowledgeApplePurchase(receipt, planII string) (string,
 	return lc.client.VerifySubscription(lc.ctx, account.AppleService, params)
 }
 
+func (lc *LanternCore) RestoreGooglePlayPurchase(purchaseToken string) (string, error) {
+	params := map[string]string{
+		"purchaseToken": purchaseToken,
+	}
+	resp, err := lc.client.RestoreSubscription(lc.ctx, account.GoogleService, params)
+	if err != nil {
+		return "", err
+	}
+	data, err := json.Marshal(resp)
+	if err != nil {
+		return "", fmt.Errorf("error marshalling restore google play purchase response: %w", err)
+	}
+	return string(data), nil
+}
+
+func (lc *LanternCore) RestoreApplePurchase(receipt string) (string, error) {
+	params := map[string]string{
+		"receipt": receipt,
+	}
+	resp, err := lc.client.RestoreSubscription(lc.ctx, account.AppleService, params)
+	if err != nil {
+		return "", err
+	}
+	data, err := json.Marshal(resp)
+	if err != nil {
+		return "", fmt.Errorf("error marshalling restore apple purchase response: %w", err)
+	}
+	return string(data), nil
+}
+
 func (lc *LanternCore) SubscriptionPaymentRedirectURL(redirectBody account.PaymentRedirectData) (string, error) {
 	return lc.client.SubscriptionPaymentRedirectURL(lc.ctx, redirectBody)
 }

lantern-core/mobile/mobile.go

@@ -565,6 +565,47 @@ func AcknowledgeApplePurchase(receipt, planII string) (string, error) {
 	})
 }
 
+func RestoreGooglePlayPurchase(purchaseToken string) (string, error) {
+	return withCoreR(func(c lanterncore.Core) (string, error) {
+		return restoreSubscription(c, c.RestoreGooglePlayPurchase, purchaseToken)
+	})
+}
+
+func RestoreApplePurchase(receipt string) (string, error) {
+	return withCoreR(func(c lanterncore.Core) (string, error) {
+		return restoreSubscription(c, c.RestoreApplePurchase, receipt)
+	})
+}
+
+func restoreSubscription(c lanterncore.Core, fn func(string) (string, error), token string) (string, error) {
+	data, err := fn(token)
+	if err != nil {
+		return "", err
+	}
+	var resp account.RestoreSubscriptionResponse
+	if err := json.Unmarshal([]byte(data), &resp); err != nil {
+		return "", fmt.Errorf("error unmarshalling restore subscription response: %v", err)
+	}
+	if resp.ActualUserID != 0 && resp.ActualUserToken != "" {
+		/// Restore was made on a different account; switch to it
+		slog.Info("Restore made on a different account, switching accounts", "actualUserId", resp.ActualUserID)
+		if err := c.PatchSettings(settings.Settings{
+			settings.UserIDKey: fmt.Sprintf("%d", resp.ActualUserID),
+			settings.TokenKey:  resp.ActualUserToken,
+		}); err != nil {
+			return "", fmt.Errorf("error updating settings after account switch: %v", err)
+		}
+		userData, err := FetchUserData()
+		if err != nil {
+			return "", err
+		}
+		slog.Debug("fetched user data after account switch", "userdata", userData)
+		return userData, nil
+	}
+	/// Restore was made on the same account, just return "" to indicate success
+	return "", nil
+}
+
 func PaymentRedirect(provider, planId, email string) (string, error) {
 	return withCoreR(func(c lanterncore.Core) (string, error) { return c.PaymentRedirect(provider, planId, email) })
 

lib/core/services/app_purchase.dart

@@ -28,6 +28,15 @@ class AppPurchase {
   // Track what plan the user selected
   String? _pendingPlanId;
 
+  // True while a restore flow is in progress; restored receipts should be
+  // acknowledged so the backend can reassociate the user, even when the
+  // device has no active subscription cached locally.
+  bool _isRestoreFlow = false;
+
+  // Set when a restore flow processes at least one purchase, so we can
+  // report "no purchases found" if the platform yields no receipts.
+  bool _restoreProcessedAny = false;
+
   void init() {
     if (PlatformUtils.isDesktop || _subscription != null) {
       return;
@@ -173,6 +182,32 @@ class AppPurchase {
     }
   }
 
+  /// Restores prior purchases from the platform store.
+  ///
+  /// On iOS this triggers StoreKit's restore flow; on Android it surfaces
+  /// active Google Play Billing purchases through the same purchase stream.
+  /// Restored receipts are acknowledged with the backend so the current user
+  /// (or the user matching the receipt, if unauthenticated) is associated
+  /// with the subscription.
+  Future<void> restorePurchases({
+    required PaymentSuccessCallback onSuccess,
+    required PaymentErrorCallback onError,
+  }) async {
+    _onSuccess = onSuccess;
+    _onError = onError;
+    _isRestoreFlow = true;
+    _pendingPlanId = null;
+
+    try {
+      appLogger.info('[AppPurchase] Initiating restore purchases');
+      await _inAppPurchase.restorePurchases();
+    } catch (e, st) {
+      appLogger.error('[AppPurchase] Error restoring purchases', e, st);
+      _isRestoreFlow = false;
+      _onError?.call('Error restoring purchases: $e');
+    }
+  }
+
   Future<void> _onPurchaseUpdates(List<PurchaseDetails> purchases) async {
     appLogger.info(
       '[AppPurchase] Received purchase updates: ${purchases.length}',
@@ -206,12 +241,26 @@ class AppPurchase {
         /// Purchase is pending (e.g. deferred payment method on Android).
         /// Dismiss loading and inform the user — the purchase will complete
         /// asynchronously when the payment is confirmed.
-        appLogger.info('[AppPurchase] Purchase is pending: ${purchaseDetails.productID}');
-        _onError?.call("Purchase is pending. You will be notified when it completes.");
+        appLogger.info(
+          '[AppPurchase] Purchase is pending: ${purchaseDetails.productID}',
+        );
+        _onError?.call(
+          "Purchase is pending. You will be notified when it completes.",
+        );
         return;
       }
       if (status == PurchaseStatus.purchased ||
           status == PurchaseStatus.restored) {
+        /// During an explicit restore flow, skip the backend acknowledge call
+        if (_isRestoreFlow) {
+          appLogger.info(
+            '[AppPurchase] Restore flow: delegating backend call to onSuccess',
+          );
+          await _finalize(purchaseDetails);
+          _onSuccess?.call(purchaseDetails);
+          return;
+        }
+
         /// Apple sends purchase updates for previously purchased items when the app starts.
         /// This check prevents processing the same subscription multiple times.
         if (await _checkIfAlreadyPurchased()) {
@@ -272,6 +321,7 @@ class AppPurchase {
       appLogger.error('[AppPurchase] Error finalizing purchase: $e', e);
     } finally {
       _pendingPlanId = null;
+      _isRestoreFlow = false;
     }
   }
 
@@ -314,7 +364,8 @@ class AppPurchase {
       return null;
     }, (user) => user);
 
-    final user = fetchedUser ??
+    final user =
+        fetchedUser ??
         (await lanternService.getUserData()).fold((failure) {
           appLogger.warning(
             '[AppPurchase] Failed to load cached user data for purchase check: ${failure.error}',
@@ -327,8 +378,8 @@ class AppPurchase {
     }
 
     final userLevel = user.legacyUserData.userLevel.toLowerCase();
-    final subscriptionStatus =
-        user.legacyUserData.subscriptionData.status.toLowerCase();
+    final subscriptionStatus = user.legacyUserData.subscriptionData.status
+        .toLowerCase();
 
     return userLevel == 'pro' || subscriptionStatus == 'active';
   }
@@ -362,5 +413,6 @@ class AppPurchase {
     _onSuccess = null;
     _onError = null;
     _pendingPlanId = null;
+    _isRestoreFlow = false;
   }
 }

lib/features/auth/sign_in_email.dart

@@ -90,7 +90,7 @@ class SignInEmail extends HookConsumerWidget {
                 boldOnPressed: () {
                   appRouter.push(Plans());
                 },
-              )
+              ),
             ],
           ),
         ),

lib/features/plans/plans.dart

@@ -10,6 +10,7 @@ import 'package:lantern/core/services/app_purchase.dart';
 import 'package:lantern/core/services/injection_container.dart';
 import 'package:lantern/core/utils/formatter.dart';
 import 'package:lantern/core/utils/screen_utils.dart';
+import 'package:lantern/core/widgets/app_rich_text.dart';
 import 'package:lantern/core/widgets/loading_indicator.dart';
 import 'package:lantern/features/home/provider/app_setting_notifier.dart';
 import 'package:lantern/features/home/provider/home_notifier.dart';
@@ -126,6 +127,17 @@ class _PlansState extends ConsumerState<Plans> {
                     onPressed: onGetLanternProTap,
                   ),
                 ),
+                if (isStoreVersion()) ...[
+                  SizedBox(height: defaultSize),
+                  Center(
+                    child: AppRichText(
+                      texts: '${'already_purchased'.i18n} ',
+                      boldTexts: 'restore_purchase'.i18n,
+                      boldUnderline: true,
+                      boldOnPressed: _restorePurchaseFlow,
+                    ),
+                  ),
+                ],
                 if (PlatformUtils.isIOS) ...{
                   SizedBox(height: defaultSize),
                   Padding(
@@ -207,14 +219,6 @@ class _PlansState extends ConsumerState<Plans> {
                 );
               },
             ),
-            DividerSpace(),
-            AppTile(
-              icon: AppImagePaths.restorePurchase,
-              label: 'restore_purchase'.i18n,
-              onPressed: () {
-                appRouter.popAndPush(SignInEmail());
-              },
-            ),
           ],
         );
       },
@@ -464,4 +468,21 @@ class _PlansState extends ConsumerState<Plans> {
       );
     }
   }
+
+  Future<void> _restorePurchaseFlow() async {
+    try {
+      final appPurchase = sl<AppPurchase>();
+      await appPurchase.restorePurchases(
+        onSuccess: (_) async {},
+        onError: (error) {},
+      );
+    } catch (e, st) {
+      appLogger.error('Error initiating restore purchase flow: $e', st);
+      AppDialog.errorDialog(
+        context: context,
+        title: 'error'.i18n,
+        content: e.localizedDescription,
+      );
+    }
+  }
 }